Articles for releasing substances, such as sanitizing, deodorizing, freshening, neutralizing or insect repelling substances, into the air are well-known. For example, air freshening articles typically comprise a housing and a separate air freshener composition located within the housing. Typically, the composition is removable from the housing so that upon its exhaustion, it may be removed and replaced.
There are, however, a number of disadvantages associated with the prior art designs. First, by locating the composition within the housing, it may be difficult to know when the composition has been exhausted. Second, labor and material costs are increased by requiring someone to check on the status of the composition which often is not easily discernable and, if it is exhausted, remove it from its housing and replace it with a new composition.
Some prior art designs have electronic monitors that provide an external indication of the status of the composition, but such monitors are expensive, unreliable at times, require maintenance and upkeep themselves and are prone to failure. Further, these electronic monitors serve at the pleasure of the power source to which they are connected. If the power source becomes interrupted or altogether fails or expires, such as with a battery, the ability of the article to release appreciable amounts of the substance, if any at all, may be nil. Failure or malfunction of the monitor is particularly problematic when there is still composition left to be released.
It would therefore be advantageous to provide a simple, inexpensive, reliable and easy to use visual indication when a composition has been exhausted and for that composition to effectively be released into the air. It would also be advantageous for the dispenser to itself be constructed of the volatile material to reduce cost, decrease complexity, and increase ease of use and effectiveness.